Roofing material varies widely and has been the subject of much innovation, as shown by a review of the prior art. Conventional roofing material, such as tile, concrete, or composition tar paper is heavy, requires a great deal of manual labor to install, and requires significant maintenance over time. Attempts have been made to address these difficulties, but prior to this invention no satisfactory solution existed.
Examples of prior art efforts have been found but have been limited to molded plastic tiles which may be interlocked at their adjacent edges and which are formed with nailing tabs or the like for securement to the underlying roof structure.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention, however, the following U.S. patents were considered related:
______________________________________ U.S. Pat. No. Inventor Filing Date ______________________________________ 4,680,911 Davis et al Jul. 21, 1987 4,522,002 Davis et al Jun. 11, 1985 4,343,126 Hoofe Aug. 10, 1982 4,251,967 Hoofe Feb. 24, 1981 3,862,532 Markos Jan. 28, 1975 3,783,570 Storch Jan. 8, 1974 3,579,940 Greenleaf May 25, 1971 2,119,921 Levy Jun. 7, 1938 ______________________________________
An example of a prior art roof tile is shown in the U.S. Patent issued to Markos. This tile construction is in the form of a planar top wall formed on its underside with longitudinal ribs and along its opposite extremities with interlocking channels. Such tiles, while being satisfactory for their intended use, fail to incorporate socket and pin construction at the upper and lower extremities for interlocking together and further fail to incorporate underlying support grid of wall segments which possess sufficient structural integrity to enable a tile constructed of relatively economical polyethylene to possess the necessary structural soundness for practical applications.
Storch teaches a roofing system with sealing and fastening means on the longitudinal and lateral edges of adjacent tiles. Further, special sections are included for hip peaks, valleys, and ridges with filler pieces to adjust for length. The material of construction is molded resinous plastic material.
Greenleaf employs molded plastic including a synthetic polymer composition material with nailing bosses positioned adjacent to an upturned flange on the top end of a planar top panel. An upstanding transverse flange is included on the resting flange on the top edge of the tile acting as a dam. Notches are also included in integral ribs to receive the upturning flange. In one embodiment the upstanding flange lockingly engages the downwardly directed ribs to prevent direct upward lifting of the upper tile. Further, Greenleafs tiles are flat, not corrugated, as in the present invention.
Levy uses basic principles of roof tiles on constructional toys employing elements, such as bricks adapted to be connected one with the other by means of pegs. The integral pegs are forced into apertures or sockets and because of the resiliency of the material and flat portions, along with an enlarged head, the elements snap together preventing inadvertent withdrawal of the peg.
The remaining cited prior art, while satisfactory for their intended purpose, suffer the shortcoming that they do not provide for secure fastening of one to the other for interlocking thereof to prevent the tile from being blown from the roof or becoming disattached therefrom in such a manner as to lend to water seepage or direct leakage into the underlying roof structure.